hawk1943
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Hi There,
Can anyone offer us some words of advice...
Basically I'm working on a project that needs to be run off a 12V car battery as standard AA batteries might not last long enough...
But I wish to use the AA batteries as a back up supply in case the Lead Acid Battery runs out half way through the experiment...
So what I am looking for is some advice on how to measure the actual voltage of the Lead Acid Battery, as the PIC 16F877 that I am using cannot safely measure that sort of input voltage...
So can I use a potential divider on RA0 which is the A/D side of the PIC to work out what voltage level I am at or is there a better method?
Also what would I use for a reference voltage...
Can anyone offer us some words of advice...
Basically I'm working on a project that needs to be run off a 12V car battery as standard AA batteries might not last long enough...
But I wish to use the AA batteries as a back up supply in case the Lead Acid Battery runs out half way through the experiment...
So what I am looking for is some advice on how to measure the actual voltage of the Lead Acid Battery, as the PIC 16F877 that I am using cannot safely measure that sort of input voltage...
So can I use a potential divider on RA0 which is the A/D side of the PIC to work out what voltage level I am at or is there a better method?
Also what would I use for a reference voltage...